No, in the set size action in your screenshot where you set the width to (320 - (Sprite.X/7)), you need to set it to -(320 - (Sprite.X/7)) if the sprite is mirrored.
In other words:
if not mirrored: set width to (320 - (Sprite.X/7))
if mirrored: set width to -(320 - (Sprite.X/7))